Data dependencies in database with incomplete information
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To get more meaning of incomplete information, a predicate way is proposed to represent the nulls. The concepts of functional and multivalued dependencies are extended in the environment which allows nulls in a database relation. The inference rules which can be applied to the extended dependencies are investigated. Finally it is shown that the rules are complete for the family of extended functional and multivalued dependencies.
KeywordsRelational Database Incomplete Information Functional Dependency Inference Rule Data Dependency
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- W. W. Armstrong, Dependency structures of data base relation, Proc. IFIP 1974, North-Holland, Amsterdam, 1974.Google Scholar
- C. Beeri, R. Fagin, and J.H. Howard, A complete axiomatization for functional and multivalued dependencies in database relations, ACM-SIGMOD 77.Google Scholar
- He Jichao, The introducing and processing of nulls in relation model,Chinese Journal of Computers,10:8 (1987).Google Scholar
- He Jichao, and Zhang Yan, A model of incomplete information database and its dependency structures, The International Pre-VLDB’86 Symposium, 1986.Google Scholar
- T. Imielinski, and W. Lipski, Jr., Incomplete information and dependencies in relational database, Proc. ACM-SICMOD, 1983.Google Scholar
- Y.E. Lien, Multivalued dependencies with null values in relational databases, Proc. 5th Internat. Conf. on VLDB, 1979.Google Scholar
- D. Maier, The Theory of Relational Databases, 1983.Google Scholar
- J.D. Ullman, Principles of Database System, 2nd ed., Pitman Publishing Ltd., 1982.Google Scholar
- Y. Vassiliou, Functional dependencies and incomplete information, Proc. 6th Internat. Conf. on VLDB, 1980.Google Scholar